It is known that creating a vortex in the fluid contained in a vessel or compartment is an effective means for mixing the contents of the vessel. Common laboratory vortexers use a support cup or a resilient vessel receiving surface mounted eccentrically on a motor in order to translate the lower part of a vessel in a circular path or orbit at a high speed and thereby create an effective vortex in the fluid contained in the vessel. Exemplary of this type of device are those disclosed in U.S. Pat. No. 4,555,183 (Thomas) and U.S. Pat. No. 3,850,580 (Moore et al.). These devices are manual in that an operator is required to hold the vessel in contact with the eccentrically movable means to create the vortex in the fluid disposed in the vessel.
Such vortex type mixer would be extremely advantageous in an automated chemical analysis instrument as it is noninvasive and therefore avoids the concern of contamination associated with an improperly cleaned invasive mixing means.
Unfortunately, when the bottom of a vessel or compartment is orbited to create a vortex, it is difficult to maintain the vessel's lid structure sealed. This is particularly true when there are multicompartments and one is orbited while the remainder remain stationary.
Often some of the reagents held in the various compartments are in the form of tabletted reagents which must be hydrated. It is known to utilize ultrasonic energy to facilitate the hydration or dissolving process. One such sonication technique is described in U.S. Pat. No. 4,720,374 issued Jan. 19, 1988 to Ramachandran. While entirely a satisfactory procedure, the application of ultrasonic energy is somewhat costly.
It is desirable in such automated chemical analyzers to store several reagents in contiguous common reagent vessels. Such a common multivessel container is sold today in an instrument known as the Dimension Chemical Analyzers by E. I. du Pont de Nemours and Company, Wilmington, Del. Such strip is described in Ramachandran. This common container is in the form of a container strip which includes a rigid peripheral band formed of an inert plastic. The band is either joined to or formed integrally with each of the vessels such that the container strip generally tapers in a substantially elongated wedge-like manner from a first edge to a second edge. The wedge-shaped plan profile for the container strip facilitates the mounting of a plurality of such strips in a circumferentially adjacent, generally radially extending relationship across a rotatable reagent carrying plate. The tops of the vessels are sealed with a suitable laminate that prevents gas and vapor escape and yet permits penetration by a probe for aspiration, etc. The plastic used for the Dimension.TM. receptacle is polyethylene and the laminate is a three-ply laminate of a polyester film, a polyvinylidene coating on the polyester film, and finally a sheet of polyethylene which is adhered to the coating. The laminate is sealed to the peripheral surface of the polyethylene vessels with the polyethylene sheet contacting the vessel rims.
These prior art multivessel containers do not facilitate vortex mixing of only one of the several vessels comprising the container.
When storing a liquid reagent or specimen, care must be exercised to minimize evaporation. Simultaneously, however, whatever structure is used to inhibit evaporation must be compatible with the requirements of access to the liquid as by an aspirating probe during use. The Ramachandran patent describes such a lid which reduces air and vapor transmission through the top of the lid. By isolating the vessels and thereby forming multivessel containers, contamination between vessels is also reduced.
The lid structure described by Ramachandran is formed of conjoined upper and lower sheets of material. One of the sheets has a receptacle formed therein which receives an elastomeric self-healing pad. A portion of the conjoined first and second sheets forms a sealing flange which completely surrounds the periphery of the receptacle and which provides a surface whereby the lid may be secured by the container.